A voltage controlled oscillator (VCO) is an electronic oscillator with an oscillation frequency controlled by a voltage input. The applied input voltage determines the oscillation frequency, consequently, modulating signals applied to control input may cause frequency modulation (FM) or phase modulation (PM). In some cases, a voltage controlled oscillator may be part of a phase-locked loop.
Traditional voltage controlled oscillators are inadequate for obtaining a suitable frequency for systems at voltages close to or lower than a threshold voltage of a main transconductance cell (GM cell) associated with the voltage controlled oscillator. There is thus a need for addressing these and/or other issues associated with the prior art.